In order to protect an occupant in an emergency or in a collision of a vehicle, a side-wall airbag device is used. The airbag device is attached to an upper part of a side wall, inflates and deploys an airbag like a curtain, and receives and protects the occupant's head within the vehicle. In a known related-art airbag device of this type, an airbag is rolled such that the rolled portion faces the vehicle exterior side (see PTL 1).
In the related-art airbag device, the airbag is deployed along a window, while being unrolled and pressed against a window glass, and is inflated between the side wall and the occupant. In recent years, to prevent an occupant from being ejected from a vehicle, an airbag is required to inflate and deploy within the vehicle cabin, even when a window is open. However, in the related-art airbag device, the airbag is pushed toward the outside of the vehicle, so, when the window is open, the airbag might be pushed out of the vehicle through the opening of the window. Therefore, it is difficult to cause the airbag to reliably inflate and deploy within the vehicle cabin.
Another known related-art airbag device is configured to push, with a strap, an inflatable section of an airbag toward a side wall, while the airbag is being deployed (see PTL 2).
Also in this airbag device, when the window is open, the airbag might be pushed out of the vehicle through the opening of the window. Thus, it is difficult to cause the airbag to reliably inflate and deploy within the vehicle cabin.